Automatic brake-adjuster



I (NoMOdeL) J. B. BURNS.

AUTOMATIUBR'AKE ADJUSTER.

No. 402,503. Patented Apr; 30; 1889.

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, UNITED STATES PATENT, OFFICE.

JOHN B. BURNS, OF INDIANAPOLIS, INDIANA, ASSIGNOR OF ONE-HALF TO ELISHAD. EAMES, OF WATERTOWVN, NEIV YORK.

AUTOMATIC BRAKE-ADJUSTER.

SPEGIFIOATION forming part of Letters Patent No. 402,503, dated April30, 1889.

- 7 Application filedSeptember 22,1888. Serial No. 286,091. (No model.)

To all whom, it mag} concern:

Be it known that I, JOHN B. BURNS, of Indi- The object of thisinvention-is to preserve,

automatically, the adjustment of the brakeshoes to the normal orprearranged distance from the Wheels intended to exist when brakes areoif, so that upon the wear of the shoes the increased amount of spacebetween the shoes and the wheels will be at once taken up and theoriginal distance between the shoes and wheels existing when the brakesare off reestablished. Various devices for effecting such a result havebeen projected, some of which have attained a greater or less degree ofsuccess. Of such may be mentioned Patent No. 352,444, granted November9, 1886, to John B. Burns, and Patent No. 354,401, granted December 14,1886, to Elisha D. Eames.

My present invention, which embodies the principle set forth in the saidtwo patents, is designed to simplify, cheapen, and render moreeffective, safe, and reliable the mechanical appliances used.

In the accompanying drawings, Figure 1 is an elevation of a pair of carwheels with their brakes and appendages, showing the application theretoof my invention. Fig. 2 is a perspective view, upon an enlarged scale,of the parts entering chiefly into the invention detached. Fig. 3 is asectional view of a detail on the line a b, Fig. 2. Fig. 4is a similarsection upon the line 0 d of the same figure.

Similar letters of reference indicate similar parts of the invention inthe respective figures.-

neled for the greater part of its length to a depth and width equal tothe size in crosssection of the lower brakerod, E, which fits and isadapted to slide therein. It is not nec essary, however, that the bottomshould be closed, as it may be entirely open, except for so much of thelength at the inner end ofthe connection F as maybe required to hold ittogether and for strength. The inner end of the connection is shaped asseen in the cross-section, Fig. 4, and in Fig. 2that is to say, it formsa strap, shackle, or close bearing, f, entirely, but loosely,surrounding the rod E.

H is the link or rod pivoted at its outer end to the brake-lever D bythe pin d. The said end of the link or rod H is forked, as at d,tostraddle the lever D, and the fork is provided with a slot, (2 in whichthe pivotal pin d is adapted to havea movement equal to the predetermined distance between the brake-shoes and the wheels when brakesare 01f. The in- ,ner end of the link or rod His furnished with a strapor shackle, h,which fits loosely over the lower brake-rod, E, and isadapted to work thereon, as hereinafter described. It will be understoodthat the opposite end of the lower brake-rod, E, is pivoted to thebrake-lever D.

The inner end of the short connection F is provided at its lower sidewith a hooked bracket or proj ection f with its cavity turned up, inwhich the lower end of a steel link, I,

- surrounding the brake-rod E rests, while the corresponding end'of thelink or rod H carries a similar hooked projection, f but with its cavityturned down, in which the upper end of a second steel link, I, (alsosurrounding the brake-rod E,) rests. The steel links are preferablyaccurately fitted to the sides of the brake-rod E, so as to admit of nolateral play, but are permitted to have a slight swinging movement inthe cavities of the hooked projections f f, as will be more particularlypointed out.

The operation is as follows: The distance which the brake-shoes aredesigned to move in setting the brakes is, as has been stated, thedistance which the pin dis capable of moving in the slot (1 of the rodII. It is therefore seen that so long as the brake-shoes (they havingbeen adjusted to have the required movement) are unworn the lever Dwill, in the act of setting the brakes, only move a distance sufficientto carry the pin d the length of the slot (1 and the link or rod II willtherefore not be moved but wear of the shoes having occurred, in orderto bring the shoes up to the wheels a greater movement of the lever Dbecomes necessary,when the link or rod H being drawn upon and the strapor shackle I'I moving upon the brake-rod E, the steel link I is divertedfrom its vertical position on the brake-rod to an inclined position,swinging, as it were, in the cavity of the hooked projection f andbinding the top edge of the brake-rod E, shifting it toward the lever D,and consequently shortening the connections between the brakeshocs,taking up the slack, and restoring the distance which normally existedbetween the shoes,when off, and the wheels. The other steel link, I,acts exactly in the reverse manner, viz., to grip the brake-rod E andprevent its back movement upon the back motion of the lever D. It willbe seen that the action is entirely automatic, and that the prescribedmovement of the brake-shoes in the act of braking is always maintained.

The movement of the brake-rod E toward the lever D is checked by the endof the rod striking a pin, 1', standing across the forked end of theshort connection F, while the movement of the brake-rod E in an oppositedirection is limited by its pin i coming in contact with the shoulder kof the short connection F.

Having described my invention, I claim- In a brake mechanism, a brakelever, a short connection pivoted thereto, a brake-rod adapted to slideupon the short connectioma rod pivoted by means of a slot and pin to thebrake-lever, and having at its inner end a strap or shackle, combinedwith a link surrounding the brake-rod and inloose engagement at itsupper end with said shackle, and a second similar link also surroundingthe brake-rod, but in loose engagement with the inner end of the shortconnection, substantially as set forth, the first link being adapted togrip the brake-rod as the brake-lever is moved to shorten said rod andthe second link to detain the brake-rod and prevent its return movementupon the opposite motion of the brake-lever, as described.

In testimony whereof I have hereunto set my hand and seal.

, JOHN B. BURNS. [L. s.]

\Vitnesses:

W. M. COVAL, LEWIS A. STONEMAN.

